1. Technical Field
The present invention relates to a vacuum valve and a vacuum pump attached to the vacuum valve.
2. Background Art
In a vacuum processing device (e.g., a film formation device or an etching device) for manufacturing a semiconductor, a flat panel display, a touchscreen, etc., film formation processing or etching processing is performed while the amount of process gas to be supplied is being controlled, for example. In such a vacuum processing device, a vacuum valve of which conductance is variable is provided between a process chamber and a vacuum pump. The conductance of the vacuum valve is adjusted for pressure adjustment of the process chamber.
In general, the vacuum valve of which conductance is variable changes the conductance thereof by a change in the degree of opening of a valve body (see, e.g., Patent Literature 1 (JP-A-2010-135371)). Moreover, the valve body can be fully closed, and can be used as a gate valve by operation between a fully-closed state and a fully-open state.
In the case of blackout during a process, danger avoidance processing needs to be performed. For example, in the case of a process using inflammable gas, the vacuum valve is brought into the open state upon blackout, thereby preventing accumulation of the inflammable gas in the process chamber. In the case of a process using toxic gas, the vacuum valve is brought into the fully-closed state upon blackout, thereby closing the toxic gas in the process chamber to avoid danger.
However, a backup power source is necessary for performing such danger avoidance processing. This leads to a vacuum valve cost increase.